Vue.component('message', {
template:
`<li>
<slot></slot>
</li>`
})
new Vue({
el: '#root',
})
<html>
<body>
<div id="root">
<div v-for="item in 5" :key="item">
<message>Message {{item}}</message>
</div>
</div>
</body>
<script src="https://cdn.jsdelivr.net/npm/vue"></script>
</html>